I tried removing the engine and running it only with the pinion, obviously I haven't run WOT without load because that would kill the engine, it runs smoothly. I have now reset the mesh with the photocopy paper method and took some photos and a video to let you hear/see the results.
First 3 are pics of spur/pinion, last one is a video showing the car running
https://drive.google.com/open?id=0B8...FlhT0lHVW5TaEU
https://drive.google.com/open?id=0B8...UwtMmhjSEZ1cDg
https://drive.google.com/open?id=0B8...jVoZ0hOOVc3ejQ
https://drive.google.com/open?id=0B8...VhEczRrcHIzTjQ